Electromagnetic pump



2 Sheets-Sheet l www@ H. B. HoLTHoUsE ELECTROMAGNETIC PUMP Filed May 15, 1940 Aug. 1s, 1942.

Aug. 1s, 1942.

H. B. HoLTHoUsE 2,293,684 ELECTROMAGNETIC `PUMP Filed May 13, 1940 2 Sheets-Sheet 2 Patented Aug. 1 8, 1942 2,293,684 ELECTROMAGNETIO PUMP Harry B. Holthousc,

Galvin Manufacturi Chicago, Ill., asslgnor to ng Corporation, Chicago,

Ill., a corporation of Illinois Application May 13, 1940, Serial No. 334,734 3 Claims. (Cl. 103-53) This invention relates to fluid pumps and in particular to fluid pumps of electro-magnetic type.

Fluid pumps of the prior art, which are particularly adapted for application where a relatively small capacity discharge is required, are usually -bulky in size and expensive in cost and operate efficiently with only relatively low suction lifts. These prior art pumps generally include a diaphragm or bellows for producing the pumping action and are limited `in duration of service by the fatigue limits of the diaphragm material, and in their effective pumping head by the tension or spring characteristics of the diaphragm. Since the amplitude of diaphragm deflection determines the pumping stroke, thev diaphragm is relatively large with respect to the pump iiuld passages to provide for a desired Dump capacity with a minimum deflection of the diaphragm. The life of the diaphragm is thus increased, but the bulk of the Ipump is also increased. In addition the control valves for regulating the flow of the fluid through the pump are usually arranged at some distance from the pumping chamber to increase further the bulk of the pump and hence the difficulties of its assembly in close quarters.

These disadvantages of the diaphragm pumps have been overcome to some extent by the use of electro-magnetically operated piston-type pumps. Commercially available piston-type pumps and the piston pumps of the prior art. however, include pumping chambers and control valves which are usually arranged about and at some distance from the operating solenoid. The small capacity piston-type pumps now generally used are, therefore, rather complicated in design, bulky in size, and expensive in cost and thus fail t satisfactorily eliminate the chief disadvantages of the diaphragm pump.

An object of this invention, therefore, is to provide an improved pump of electro-magnetic type. y

It is a further object of this invention to provide an electro-magnetic pump having a variable discharge.

Yet another object of this invention is to provide a reciprocating pump of electro-magnetic type which is of compact design, cheap in cost, and eicient in operation.

It is a further object of this invention to provide a solenoid actuated fuel pump for an internal combustion device having a fuel system and an ignition system, in which the solenoid is operatively arranged to effect an energization of the ignition means in the ignition system.

A feature of this inventionis the provision of a'reci-procatlng fuel pump in which the piston is operable in la cylinder having a bore substantially equal to the diameter of the pump inlet and outlet passages, and is actuated for movement in one direction by resilient means arranged in compression and located in said cylinder whereby to provide for a relatively high effective operating pressure of the piston.

Another'feature of this invention is the provision of a reciprocating pump having a tubular cylinder with a control valve at each end and with an elongated piston operable therein substantially between the cylinder ends, they piston being formed with a longitudinal fluid passage therein having a control lvalve near one of its and a fluid outlet at the opposite'end, the fluid from the inlet passing to the outlet throughv a longitudinal opening formed in the piston and the piston being self-lubricated by its complete immersion in the fluid passage through the pump;

Further objects, features and advantages of this invention will be apparent from the following. description when taken in connection with the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional elevation of one form of the invention;

Fig. 2 is a sectional in Fig. 1;

Fig. 3 is a longitudinal elevational view, in section, of a modified embodiment of vention;

Fig. 4 illustrates diagrammatically an electrical circuit for the embodiments of Figs. 1 and 3;

Fig. 5 is a fragmentary sectional view of a check valve structure which may be used in the embodiments of Figs. 1 and 3; and

Fig. 6 illustrates diagrammatically anelectrical operating circuit for the embodiments of partly the inview taken along line 2-'2 the cylinder end I4,

` effect iiuid through the passages Figs. 1 and 3 when used in the ignition system for an internal combustion device.

With reference to the drawings similarcharacters of reference shall designate similar parts throughout the several views. In Fig. 1 there is shown a reciprocating pump including a cylinder I of tubular form which is operatively associated with a piston II of elongated construction. The cylinder or sleeve Il is provided in a suitable non-magnetic material, such as die cast or brass, while the piston is provided in a magnetic material, such as iron, movement of the piston in one direction being effected on energization ofy the solenoid I2 which is mounted about the sleeve I0; the piston II operating as a solenoidal core. Fluid enters the pump at the cylinder end I3 and is discharged there from at the piston being operable the cylinder ends. The piston I I is formed with a longitudinally'r extending passage I6 of reduced section and an enlarged passage section or annular recess I1 which is in register with the passage I6 and located at the piston end I8, which is near the inlet end I3 of the cylinder I0, the recess I1 having a valve structure I9 located therein, which is operable to control the flow of the fluid through the passage I6. The inner end of the recess I1, is formed with an annular groove 22 which extends in spaced relation about the passage I6 to form an annular longitudinally extending flange 23, the ange being provided with a plurality of apertures 26 to connect the groove 22 and the passage I6, for a purpose to be later described.

The valve structure I9 located in the recess I1 includes a disc member 21 (Figs. 1 and 2) which is adapted to fit over the passage I6 and is held in the recess I1 by a plug 29 having a bore 3| therein of a diameter commensurate with the diameter of the passage I6, the inner end of the substantially between l plug being formed with a reduced section 32 toV provide an annular seat 33 for the disc valve 21. The disc v21 is tween the end 24 of the flange 23'and the annular seat 33 at the inner end of the plug 29. A spring 34 positioned in the groove 22 and arranged in compression between the disc 21 and the bottom of the groove serves to retain the disc 21 on its seat 33. Since the eflicient operation of the disc 21 is dependent upon a positive seating of the disc on the seat 33, the distance between the seat 33 and the flange end 24 is very small and equal to about twice the thickness of the disc 21, to reduce to a minimum any tilting or canting of the disc when it is raised from its seat 33. In some cases, however, it may happen that the disc 21 will be urged into seating engagement with the flange end 24. since this condition would a closing of the passage I6, the disc is formed with notches 36 in the peripheral edge thereof so that communication between the passages 3I and I6 will occur through the apertures 26, groove 22 and notches 36. A positive flow of 3| and I6 is thus assured for any position of the disc 21 from'its seated position on the seat 33. i

Suitably secured to the inlet end I3 of the cylinder IIJ is a head or valve body member 31 which is formed with a passage 38 of reduced section and a recess 39 of enlarged section, which are in register with each other and with the pump `inlet chamber 4I in the cylinder I0. The inner end of the recess 39 is formed with an annular groove 42 which extends in spaced relation about the inner end 45 of the passage 38 to provide an annuthus longitudinally movable be?,

l tween the disc lar seat 43 for a disc 44, which is operable to control the ow of the iluid through the passage 38. The disc 44 is normally maintained in seating engagement with the annular seat 43 by a spring 46, which is arranged in compression be- 44 and a shouldler 41 formed on a plug member 48, the plug member 48 being threadably secured in the recess 39. The plug 4I is formed with a passage 49 which corresponds in diameter with the passages 3| and 38, the wall portion near the inner end 50 of the .passage 48 being formed with apertures 5|, to provide for communication between the passages 38 and 49 through the spring recess 52 and the notches 53 formed in the peripheral edge of the disc 44 in the event the disc should become seated on the plug end 50, the structure and operation of tite disc 44 being similar to that of the discO21 lust described.

A head or valve body member 54'is suitably secured to the outlet end I4 of the cylinder III and is formed with a passage 56 of reduced section and a recess 51 of enlarged section, the passage 56 being arranged for alignment in the piston II. The inner end of the recess 51 is provided with an annular groove 58 which extends in a spaced relation about the passage 56 to form an annular seat 59 at the passage end 6|. A disc-62, similar to the discsA 21 and 44 previously described, is normally maintained in seating engagement on the seat 59 by a compression spring 63 which is held in the recess 51 by a plug member 64, the member 64 being formed with a passage 66 therethrough which corresponds in size with the passages I6 and 56. Also, similarly to the discs 21 and 4.4, the disc 62 is formed with peripheral notches 61 to provide for a flow of fluid therethrough and through the spring groove 68 and apertures 69, in the event of its seating on the end 10 of the passage 66. All of the discs 21, 44, and 62 are thus adapted to be of a diameter substantially equal to that of "the fluid"passages in the pumpmand may be provided in a phenolic or resinous cnipositionmate- -rial, which is of light weight and imperviousA-1v` movement of the piston I0, towards the right, is

obtained by a spring 1I which is located in the inlet chamber 4| and arranged in compression between the piston end I8 and the valve body member 31. As shown in Fig. 4, the solenoid I2 is selectively energized by an energizing circuit which includes a battery 12 connected in series with the solenoid I2 through contact arms 13, contact between the arms 13 being effected by theoperation of a' cam 14 which in the case of the pump being employed in the fuel system oi an internal combustion engine may be mounted on the engine cam shaft. In the application of the pump for use in a heater of internal combustion type the cam shaft of a motor for the air circulating or air supply fans. On closing of the contacts 13 the piston II is moved to the left, which movement effects a reduction in the size of the chamber 4I and a consequent increase in the pressure of the fluid in such chamber, the increased pressure acting to seat the disc 44 on its seat 43 whereby to prevent any flow of fluid outward from the pump with the passage I6 I 14 Amay be mounted on the through the passage 33 and acting further to force the disc 21 from its seat 33 to provide for a flow of the fluid from the chamber 4|, through through the passages 3| and I6 into the expanding outlet chamber 16 which is formed at the cylinder end I4, as indicated by the dotted lines 11. The chambers 4I and 16, when fully expanded, are of substantially the same size so that the uid pressure in the chamber 16 is substantially equal to the fluid pressure in the chamber 4| prior to its reduction by movement of the piston IIJ. Since this pressure is on the order of the pressure in the fuel supply line and hence in the passage 38, as will be later explained, a relatively Alow pressure exerted by the spring 68 is sufficient to maintain the disc 62 on its seat 59; the springs 34 and 52 being substantially similar to spring 68. Immediately upon opening of the contacts '13, by the continued rotation of the cam 14, the solenoid |2 is de-energized and the spring 1I acts to force the piston I0 towards the right. This movement of the piston I produces a suction pressure in the inlet chamber 4I, due to its being expanded, whereby the disc 44 is opened to provide for a flow of fluid through the passages 38 and 49 into the inlet chamber 4I;

' the fluid admitted to the chamber 4I being at substantially supply line pressure. The fluid in the outlet chamber 16 is compressed due to such chamber being contracted, this increase in pressure providing for a closing of the disc 21 and for an opening of the disc 62 whereby the fluid under pressure is discharged from the pump through the passages 56 and 66. Upon a reclosing of the contacts 13 the solenoid I2 is again energized and the cycle of the piston I0 is repeated.

It is thus seen that the disc valves 44, 21 and 62 all open in the direction of fluid ow and are operable in response to the fluid pressures produced in the reducible'and expansible chambers 4| and 16, by the reciprocating action of the piston I| inthe cylinder I0. 'I'his arrangement of the valves provides for a successive moving of the fluid through the pump, the fluid irst being admitted into the inlet chamber 4| through the passages 38 and 49 on movement of the piston toward the right, then passed through the passages 3| and |6 in the pistonV |I tothe chamber 16 on movement of the piston toward the left, and finally ejected from the pump, and specilically from the outlet chamberA 16, through the passages 6| and 66 on movement of the piston toward the right. It is to be noted that the movement of the piston I| toward the right provides for the drawing of fluid into the chamber 4| through the valve 44, and-the discharge of the fluid from the chamber 16 through the valve 62, so that the suction action of the pump occurs concurrently with its ejection action.

The diameter of thev bore of cylinder I8 is of a size sufficient to provide for a piston having passages 3| and I6 which correspond in diameter with the passages 38 and 66, which represent substantially, the diameter of the fluid supply line (not shown), which is adapted for connection to the head members 31 and 54. The size of the pump is thus reduced to a minimum, and the arrangement of the valves and piston to provide for an entire pumping. action in the cylinder 0, provides for a pump having a pump chamber which is formed as a part of the fuel supply line. The location of the piston II in the'fluid supply line portion formed by the cylinder I0, effects a continuous lubrication of the elongated piston II to provide forits free operation in the cylinder I0. Location of the spring 1I .within the cylinder III provides for the full effective spring pressure being utilized in operating the piston so that a high maximum iiuid pressure is produced in the discharge passage es. That is, the

spring pressure exerted by the spring 1I is distributed only over the piston sectional area, and since this area is relatively small, being of the 1 order of about of a, square inch, a spring pressure of only about 1 pound per square inch will effect a pump operating pressure of about 10 pounds per square inch. This feature of the present invention provides for a pump of small capacity which is adapted to operate efficiently with high'suction lifts, and the pump, therefore, may be arranged or assembled over a wide range of positions in' the particular fluid system in which it is employed.

In the reciprocating movement of the Cpiston II in the cylinder I 0 the spring 1| operates to move the piston to the right a -distance about equal to the movement of the piston to the left as imparted by the action of the solenoid I2. Any variation, therefore, in the leftward travel of the piston II will provide a corresponding variation in the movement of the piston toward the right.` Since the solenoid I2, on energizetionV thereof, acts to draw or attract the yiron piston inwardly of the non-magnetic sleeve or cylinder I0 to a neutral position,\which occurs when. the piston end 18 is substantially flush with the solenoid end- I9, a. movement of the solenoid on the cylinder I0 toward the right will effect a shorter operating stroke of the piston II; a maximum str'oke being effected when the solenoid is positioned at the cylinder end I3. A variable pump capacity is thus obtained by adjusting or moving'the solenoid I2 relative to the cylinder Ill;4 a desired adjustment being maintained by adjusting nuts 8| which are arranged at opposite ends of the solenoid I2.

In some installations, such as gravity feed systems, the fuel in the supply line may be subjected to varying pressures and to pressures which are in excess of the pressures normally exerted by the valve springs 52, 34, and 68 on the discs 44, 21, and 62, respectively, so that when the pump is not operating this pressure might be sufficiently high to open or crack the valves 44, 21 and 62 and thus provide for a flow of fuel` through the pump To eliminate any such occurrence of fuel leakage through the pump the piston II' (Fig. 5) may be formed at its discharge end 'I8' with a valve portion 82, which is adapted for seating engagement with 'a valve seat 83 formed at the inner end of the passage 56 in the head or valve body member 54. Seating of the valve portion 82 in the valve seat 83 occurs at the extreme end of the discharge stroke of the piston as effected by the spring 1I. Fuel communication between the passages I6 and 56 during normal operation of the pump is obtained through apertures 84, which are formed in the valve portion 82 and are 1ocated in such portion so as to be closed by the seating engagement of the portion 82 in the valve seat 83. During operation of the pump, therefore, the pump discharge action is stopped upon the engagement of the piston I I' in the head member 54', so that ythe check or lock-out valve 82-83 functions as a discharge cutoff. When the pump is not in operation the engagement of the rvalve portion 82 with the valve seat 83 is maintained by the pressure of the spring 1I, so that any additional pressure in the fuel supply line above the pressure exerted by the spring 1|, servesv only to 4 further maintain this seating engagement rather than to effect a release of such engagement. Any leakage of fuel through the pump, at such times when it is not in operation. is thus positively prevented.

The embodiment of Fig. 3 includes a cylinder I4, a piston 88 and a solenoid I2 mounted about the cylinder I0. The piston 88, as viewed inFig. 3 is adapted to be moved to the right by the solenoid I2 so that discharge of the uid from the pump is effected by the action of the solenoid I2, rather than by the spring 1 I This reversed accompleted previously explained, this energization of th,

tuation of the piston 88 by the solenoid I2, as

compared to the movement of the piston I| in Fig. l is accomplished by positioning the solenoid at the end I4 of the cylinder I0, the drawing of the piston 88 to a neutral position within the sfolenoid being effected in an opposite direction. The stroke of the piston, therefore, is decreased by moving the solenoid to the left on the cylinder I0. The spring 1|' is also located at the cylinder end I4 and the pressure exerted by-the spring acts to move the piston 88 toward the left. An inlet head member 81 is secured to the cylinder end I3 and is formed with a fluid passage 88 i which is in alignment with the fluid passage 89 formed in the piston 86. The ilowof the uid through the passages 88 and 89 is controlled by check valves 9| and 92, respectively, which are of the usual type; the valves 9| and 92 being operable in response to the uid pressures occurring in the cylinder I0 and arranged to open in the direction of'fluid flow through the pump. An outlet head member 93 is securedto the cylinder end I4 and is provided with a passage 94 which is illustrated as being in communication with the outlet chamber` 18' and in alignment with the passage 89 in piston 88, the now of the fluid through passages 94 being controlled by a check valve 98 which is similar to the valves 9| and 92 and also adapted for opening in the direction of fluid flow through the pump.

The operation of the embodiment of Fig. 3 is similar to that previously explained in connection with Fig. 1; the circuit in Fig. 4 also being applicable to Fig. 3. On energization of the solenoid I2 the piston 88 is moved to the right whereby fuel is drawn through the passage 88 into the inlet chamber 4I' concurrently with the discharge of fuel through'the passage 94 from the outlet chamber 16'. On de-energization ofl the solenoid I2 the piston 89 is moved to the left by the pressure of spring 1I' to transfer the fluid from the chamber 4 I through the piston passage 89 into the outlet chamber 18'. When the solenoid I2 is again energized the cycle of operation is repeated. Y

In the employment of the invention with internal combustion devices having both a fuel feeding system and an ignition system, such as an automobile heater or automobile engine, the solenoid I2 may be used tooperate effectively as a primary winding to provide an operating voltage for the ignition means included in the usual ignition system. This application of the invention is schematically illustrated in Fig. 6, in which the solenoid I2 is mounted about the cylinder I0 and in operative association with a secondary winding' 91, the winding 91 being shown as extending about the solenoid I2. Assuming the cylinder I0 and solenoid I2 to include the structure of Fig.- 1, in which the piston is moved to the left on energization of the solenoid I2, closing of the contacts 13' by the cam 14' permits current to flow from the battery 12' through conductor 98, contacts 18' and conductor 99 to the solenoid I2, the circuit being bythe ground connection IOI. As

solenoid I2 moves the piston to the left, which movement effects a compression of the spring 1I. On opening of the solenoid circuit by an opening of the contacts 13' the solenoid I2 is de-energized, the collapse of the current flow 'therein effecting a voltage increase in the secondary winding 91, in the usual manner, which is adapted to effect a spark across the gap |04, the secondary circuit upon opening of the contacts 18' being comprised from the battery 12 of conductor`98, condenser |08, conductors 99 and I02, conductor |08, spark gap |04 and ground connection |08. Since de-energization of the solenoid I2 occurs prior to the movement of the piston I0 toward the right by the spring 1|, the spark will occur at the gap |04 before the ejection of the fuel from the outlet passage 88. The spark thus occurs in advance of the fuel discharge. In the application of the pump to an automobile heater the advance of the spark relativeto the fuel discharge does not interfere with the operation of the heater since a relatively timed occurrence of the'r fuel and spark in the heater combustion chamber is not essen- Y tial to its efllcient operation.

However, in the voperation of an internal combustion engine, a more eillcient operation of the engine is obtained by a spark which lags or follows after the fuel admission into the engine,

since the admission of the fuel and occurrence of the spark in the usual engine cylinder is relatively timed to correspond with a predetermined operating position of the engine piston. The occurrence of a fuel discharge prior to the occurv1i'e'nce of a spark-isobtained by the embodiment of Fig. 3. the circuit of Fig. 6 remaining the same. Thus on energization of the solenoid I2 the piston 88 is moved toward the right to discharge the fluid from the outlet chamber 18' through the passage 94 prior to an opening of the solenoid circuit. Since the solenoid circuit remains closed until after the fuel has been ejected from the pump, the spark at the gap |04 is thus timed to lag the admission of fuel to the engine.

The invention is thus seen to provide for a fluid pump which is of rugged construction, simple and compact in design, and adapted for efficient operation with relatively high suction lifts. The pumping action of the nuid through the Dump is controlled by an arrangement of valves which require a minimum of adjustment and replacement and which act positively at all times during pump operation. The pump chamber is formed as a part of the fuel supply line so that the pump may be arranged anywhere 6o along the length o f the supply line between the fuel source and the point of desired fuel discharge. A complete immersion of the pump piston in the fuel line provides for a self-lubricated piston, so that the piston is freely movable at all times. The invention further provides an electro-magnetic pump in which the solenoid may be utilized as a primary winding in the operation of internal combustion devices which em-' ploy both a fuel system and an ignition system,

the solenoid being operatively associated with a secondary winding for the ignition means included in the ignition system, to provide for a voltage increase in the secondary winding on a collapse of the current in the solenoid on de- Vas to completely evacuate all fluid mixtures which might be admitted thereto so that air binding, with the consequent provision of air release valves or domes, is entirely eliminated through the normal operationV of the pump.

It is to be understood that only preferred embodiments of the present invention have been c described and illustrated herein and that alterations and modifications thereof can be madewhich are within the full intended scope of the invention as defined by the appended claims.

I claim:

1. In a uid pump including a cylinder having a fluid inlet and a uid outlet with said inlet connected to a uid supply line, the combination of an elongated piston operatively associated with said cylinder and movable therein substantially between said inlet and outlet, said piston being of tubular construction and closed at one end, with the bore in said piston serving as a fluid passage and said one end being formed with a valve portion having apertures therein opening into said piston fluid passage, a body member connected to said cylinder at said outlet having a fluid discharge passage therein communicating with said piston fluid passage through said apertures, valve means in said piston for controlling the flow of uid through said piston passage, valve means at said cylinder inlet and outlet for controlling the flow of fluid through said cylinder, all of said valve means being arranged to open in the direction of fluid iiow through said cylinder and to operate in response to the fluid pressure produced in said cylinder by the reciprocating action of said piston to provide for a successive flow of the fluid through said cylinder inlet, piston passage, cylinder outlet, and discharge passage, and means including said piston valve portion for preventing a flow of iiuid through said cylinder when said pump is not operating, said body member having a valve seat thereon engageable with said valve portion when said piston is at one limit of its reciprocatory travel to close said apertures, with an increase of the uid pressure in said supply line' acting to urge said valve portion against its seat.

2. In a uid pump including a tubular cylinder having an inlet at one end and an outlet at the other end, and a tubular valved solenoidal core reciprocally movable within said cylinder between the ends thereof for drawing fluid through`said inlet and discharging it through said outlet, the combination of means for reciprocating said core in said cylinder including a solenoid adjustably mounted about said cylinder, and means operatively connected with said cylinder and solenoid for adjustably moving said solenoid axiallyof said cylinder to vary the reciprocating movement of said core.

3. In a fiuid pump, the combination of a nonmagnetic tubular cylinder having a magnetic piston of elongated construction operatively associated therewith and slidable substantially between the ends thereof, mounted on said cylinder and adapted on energization thereof to actuate said piston, said cylinder having a threaded end portion, and means for adjusting the working stroke of said piston including an adjustable member thread-v ably connected with said threaded end portion for movement axially of said cylinder, said adjustablelnember being operatively engageable with said solenoid to slidably move the same axially oi said cylinder to adjust said piston stroke.

HARRY B. HOLTHOUSE.

a solenoid slidably 

